Know Your Tongue
The tongue does far more than help you taste food – it's essential for chewing, swallowing and speech, and it can also be one of the first places that certain health conditions show up.
Q: What is the tongue made of?
The tongue is a muscular organ covered with moist, pink tissue called mucosa. Tiny bumps called papillae give it its rough texture, and thousands of taste buds cover the surface of these papillae – collections of nerve-like cells connected to nerves running into the brain. The tongue is anchored to the floor of the mouth by webs of tough tissue; the band holding down the front of the tongue is called the frenum, while the back of the tongue is anchored into the hyoid bone.
Q: What can the tongue taste?
The four basic tastes are sweet, sour, bitter and salty. The tongue is covered in nerves that detect and transmit these taste signals to the brain – and, contrary to the old idea of a "tongue map", all parts of the tongue are able to detect all four basic tastes.
Q: What tongue conditions should I know about?
A number of conditions can affect the tongue, some harmless and some worth having checked:
• Thrush (candidiasis) – a yeast, Candida albicans, overgrows on the surface of the mouth and tongue. More common in people taking steroids, with a suppressed immune system, or at either end of the age spectrum.
• Oral cancer – a growth or ulcer that appears and steadily grows. More common in people who smoke and/or drink heavily, and always worth having examined promptly.
• Macroglossia (enlarged tongue) – can have congenital, inflammatory, traumatic, cancerous or metabolic causes, including thyroid disease.
• Geographic tongue – ridges and coloured patches that migrate over the tongue's surface, periodically changing its appearance. Harmless.
• Burning mouth/tongue syndrome – a burning or scalded sensation, or unusual tastes, often linked to a mild nerve problem.
• Atrophic glossitis (bald tongue) – the tongue loses its bumpy texture and becomes smooth, sometimes due to anaemia or a B vitamin deficiency.
• Canker sores (aphthous ulcers) – small, painful ulcers that appear periodically. Not contagious, and unrelated to cold sores caused by the herpes virus.
• Oral leukoplakia – white patches that can't be scraped off. Usually benign, but can occasionally progress to oral cancer, so should be checked.
• Hairy tongue – overgrown papillae give the tongue a white or black, "hairy" appearance. Harmless, and corrected by gently cleaning the tongue.
• Herpes stomatitis – the herpes virus can, uncommonly, cause cold sores on the tongue (usually they appear on the lip instead).
• Lichen planus – a harmless condition affecting the skin or mouth, thought to be related to the immune system.
Q: When should I get a tongue problem checked?
Most tongue changes are harmless, but a sore, patch or growth that doesn't heal within a couple of weeks, is painful, or keeps coming back is worth having examined. This is especially important for anything resembling oral leukoplakia or a persistent ulcer, given the (rare) possibility of oral cancer – catching it early makes a real difference.